On-Screen Chemistry
by Rachel C. Astrid
Summary: Prompt fill for kink meme '13: Castle and Beckett find 3XK's videos of them having sex and surprisingly get off on it. Set a day or so after 5x05.


_Prompt: **Castle and Beckett find 3XK's videos of them having sex and surprisingly get off on it.**_

_I'm working on something else that plays off that episode and couldn't resist having fun with this in the meantime. Thanks, anon!_

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**On-Screen Chemistry**

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Esposito's the one to open it. Maybe that's a good thing.

He looks a little emotionally scarred, but he's also discreet when he finds Castle alone, presses the portable drive into his palm and says, "This is yours to get rid of."

One pointed look and then he's gone, off to sort through more of what Tyson left behind.

Castle takes the harddrive home with him. It waits in his pocket while the family eats, fighting for some semblance of normalcy. It waits as he and Kate indulge in one another in the privacy of his bedroom, still aching for reconnection.

It isn't until Kate's in the shower that he loads the drive onto his laptop and confirms why Esposito neglected to log and store this particular piece of evidence.

Castle would be lying if he said he wasn't intrigued. He and Kate filmed themselves once, but for all of their bluster, both of them had been a little nervous. The results were hot, but this—this is electric. Natural and raw and real. The fact that they didn't know they were on camera this time makes the scene that much more enticing and Castle can't look away.

This Kate is every bit the seductress on-screen that she is in real life. He's just had her, but the sight of her there, dimly lit and sure of what she wants as she straddles him on the bed, is enough to make him hard and wanting.

_Touch her_, he thinks, watching himself in the video and dying of frustration that his alter-ego stays relatively still when he could be nestled between her boobs or kneading her ass or kissing her senseless. _For the love of God, how are you not all over her?_

And then he realizes that Kate has been holding his wrists, pinning him as she undulates above him, and the more he picks up on the details the hotter his cheeks flush with the heat of memory. The air is still heavy with sweat and sex from tonight, but the scent only sends him back to the night on the screen.

And then, as though just to stroke his ego now, the man from the past wrestles free of Kate's grasp and traces every curve within his reach. He sucks her nipples between his teeth and slaps her breasts and works her clit and she cries out, ecstatic with the sensations he inflicts as she rides him.

Castle's lost in Kate's on-screen orgasm when his robed girlfriend emerges from the bathroom just in time to hear it.

"Seriously? Are you watching porn?"

He jerks on the bed, caught off-guard at the second Kate, the one with clean wet hair and a silky white robe and a disbelieving tone as opposed to the naked one who's telling him _not to fucking stop _about three weeks ago.

"Wait a minute," she says before he can sputter a word. "That's—"

"Yeah."

"But that's not our—"

"No."

"Then when did you—"

"I didn't." And he's just about to explain when the on-screen chemistry flares into a distraction neither one of them can even pretend to ignore.

Orgasmic Kate is still trembling with aftershocks, breathing Castle's air as he holds her face in his hands and lets the energy of arousal swell in the small space between their parted lips. Then Castle rolls them to the side, maneuvers her onto her belly and climbs off the bed. She's barely caught her breath by the time he drags her closer to the edge, grabs her hips to lift her ass and pushes into her from behind.

Her hair cascades around her face until he sweeps it back, and then he's coaxing her upright to lean back against his bare chest, her head resting against his shoulder.

He wraps one arm around her ribcage to find her breast and wraps the other over her shoulder to cradle her jaw, exquisite tenderness even as he thrusts hard. It was how he meant it in the moment, and he's not too humble to appreciate how it translates in film.

_Richard Castle, _he telepathizes to the man of three weeks ago, _look at you, you fucking star._

Of course, Kate's radiance doesn't hurt his image either. Her knees bearing her weight, she raises her hands above her, letting them scrape through his hair as though intent to feel him close even as she can't see him.

But tonight, in the telltale glow, she can see him as he was. She can see them both. He doesn't look at her; keeps his eyes fixed on the past instead.

Here and now, she says, "Castle," like her throat is made of paper.

"Right." He swallows and goes to shut off the video—because he's sure that she's figured it out now and what the hell was he thinking, watching this thing?

Evidence of their delicately clandestine romance; of Tyson's voyeurism. Either way, one little piece of evidence with the power to tear them apart. Of course she wants him to shut it off.

But she brushes his hand away and he catches her eye and—oh. _Oh._

Is it possible that she's even more aroused than he is?

She sets the laptop on the nightstand and resets the clip to the beginning she missed, leaving the video well within view. She gropes him through his dark V-neck and boxers and his hardness responds to her warmth, her touch so much more intoxicating than their recorded romp but only heightened with the sight and sound of their past pleasure.

She sits beside him where she'll have to peer over his shoulder to see the screen, but he can tell just by a series of subtle changes in her breathing that she's still watching. She suckles on his earlobe and slips her hand inside his boxers while they watch him wrestle free of her hold and come alive beneath her.

He'd shuck the shorts completely, but he can't remember how to move and Kate's already thumbing his tip and what is reality, anyway? He's caught in the middle of two sensual Kates and a confident reflection of himself, every bit of these two scenes real in some dimension, like an orgy defying the laws of time and space. Not one scrap of it staged or scripted or confined to his books.

Suddenly she tugs at his waistband, and somehow he lifts enough for her to slide the boxers off of him.

The movement helps to clear the fog a little and he chuckles. "At least one of us has the presence of mind to—"

He doesn't finish that thought because he's no longer impressed. She completely bypasses his T-shirt and her robe and sinks onto his length.

She rides him, on- and off-screen, but he doesn't wait for his cue to flip her this time. She's turned away from the laptop to straddle his lap, and he wants her to watch with him, watch them capture lightning in a bottle.

He turns them and rolls them further onto the bed, landing above her as she grips him with her thighs, the maneuver loosening her robe to expose more of her nakedness. The tips of her hair are still damp and shower-fresh, but it isn't long before their nearly-bare skin becomes slick with warm, heady sweat.

As she comes she cries out louder than appropriate even in the spacious loft, and he leans in and covers her mouth with his hand, only to find that her pleasure is in stereo—that on-screen, standing behind her, his hand slides up from her jaw to cover her mouth while she clings to his arm and bites back her moans.

But it's the look in her eyes tonight that undoes him.

They're still recuperating when they hear indistinct conversation from the laptop. Another glimpse of their life together begins to unfold, and—surprise, surprise, they're just as naked and passionate as before. He wonders whether Tyson deliberately spliced these compromising videos together for them or for the authorities who might forbid their relationship.

He wonders something else, too. "Is it weird that we're getting off on a serial killer's stalker footage of us?"

"I'm never going to apologize for enjoying you," says Kate, still rediscovering air. "What I _am _wondering is just how many videos are on here."

Castle hums at that. "Yeah. And I wonder how far Esposito got. He looked like he'd walked in on his parents."

She catches her breath but she's lost her cool. "Esposito saw that?"

"What, _that _squicks you out? Did you miss the part about the serial killer who filmed our homemade porn?"

"The serial killer is dead," she counters. "Terrifying and despicable, yes, but dead."

It rolls off his tongue maybe a little more easily and seriously than the joke he means it to be: "Are you suggesting we kill Esposito?"

She rolls her eyes, a resounding no and an expression of endearment wrapped up in one motion.

"Good," he says, "because who else will make sure no one leaks our sex tapes?" And then he beams. After tonight, he can't help it. "Not that we'd have anything to be ashamed about. Actually, if there's ever an award for this, I think we'd win."

"Yeah?"

"Yeah."

Kate clicks her tongue at him and reaches over to eject the harddrive. "I think I'm going to be the one to hold onto this."


End file.
